1. Field of the Invention
The present invention relates generally to a torsional vibration damper, in particular for a flywheel which has two inertial masses, and is installed in the drive train of a motor vehicle.
2. Background Information
German Patent No. 36 28 774 A1 discloses a torsional vibration damper which has two rotating elements which can rotate around a joint axis of rotation both together and relative to one another. One of the two rotating elements has a ring-shaped hub which is located centrally in relation to the axis of rotation. The other of the two rotating elements is rotationally guided on the hub by means of a pivot bearing. A first of the two rotating elements, in the vicinity of its outside periphery, also has a channel which is tightly sealed toward the radial outside. In the channel a coupling part, which is rotationally connected to the second of the two rotating elements, extends or projects radially. Further, at least one spring is located in the channel, which spring connects the first rotating element with rotational elasticity to the coupling part.
To fill the channel with lubricant, in particular grease, to reduce wear and to damp noise and vibrations, an opening is provided in one of the two rotation elements, radially outside the hub area. The opening, after the channel has been filled with lubricant, must be closed by means of a special cap. The preparation and installation of the cap requires some effort.